1. Field of the Invention
The present invention pertains to air handling and conditioning apparatus. More specifically, the present invention pertains to apparatus for handling, filtering and temperature conditioning of air for an enclosed space such as a building occupied by humans, computers or other heat sensitive equipment.
2. Brief Description of the Prior Art
For many years, enclosed spaces for human pursuits and habitation have been supplied with conditioned air, i.e. filtered, cooled, heated, humidity controlled air. Such conditioning of the air is especially appropriate for human comfort in warm and humid environments. This is particularly true in work place environments. If the air is not properly conditioned in a work environment, efficiency of the worker may decline and in many cases the workers physical condition may be impaired by poor quality air.
In more recent times, enclosed spaces may be provided for computers, electrical equipment and other technical equipment, instruments and processes. Such equipment may be highly sensitive to temperature and humidity changes.
An air conditioning system for an enclosed space usually provides a filter through which ambient air is drawn, an air handling unit for moving air through the system and a refrigeration unit providing a refrigerant for heat exchange with the air to cool the air prior to entry into the closed space to be conditioned. Occasionally, and frequently in some environments, it may be necessary to service and/or repair one or more of the components of an air conditioning system. This usually necessitates shutting down the entire system for the period of time necessary for the servicing or repair of the component. Such a period of time may be anywhere from a few minutes to several days. In many situations, particularly in industrial work environments, the individual workers cannot function for these periods of time without proper air conditioning. In other situations, temperatures may substantially increase so as to impair function of computers, instruments and other equipment.
Where it is important that the proper conditioning of air not be interrupted, stand by or dual air conditioning systems have been provided in which two complete air conditioning units are provided so that if one unit must be shut down for servicing and/or repair, the other can be utilized for continuous conditioning of the air. While such an arrangement solves the problem of providing continuous air conditioning, it introduces a number of associated problems. Obviously, the cost of providing a dual system is essentially doubled, the space required for a dual system is generally doubled and the maintenance and repair problems are increased. In fact, the standby units which do not operate as frequently as primary units may incur problems simply by non-operation.
Thus it could be seen that the provision of continuously conditioned air to an enclosed space is not without some problems. Alternate solutions are sought and desired, particularly in certain environments.